There are several acarocolous species that are too small to be seen without the use of some form of magnifying instrument and they abound in almost every habitat where they scavenge on waste materials, prey on other tiny invertebrates, or live as parasites on many larger species of life.

Some acarocolous mites are harmless as they exist in skin follicles, feathers, or fur; while others cause diseases or allergies.

The acarocolous ticks are blood-suckers and spread disease-causing microbes in animals.